1. Field of the Invention
The present invention relates to a method for driving tools, and more particularly to a method for driving electric hammer or impact or percussion tools
2. Description of the Prior Art
Various kinds of typical electric percussion tools, impact beating tools, or the like have been developed and provided for hammering or stapling or nailing purposes, and comprise a plunger core slidably received in a coil or solenoid, which may actuate or force the plunger core to move and thus to hammer or impact onto objects.
For example, U.S. Pat. No. 3,308,892 to Palmer, and U.S. Pat. No. 4,215,297 to Jacquemet disclose two of the typical electric percussion tools, impact beating tools, or the like and comprise a single plunger core slidably received in a single solenoid, and a spring member for recovering the plunger core back to the original position, or away from the middle portion of the solenoid.
In operation, the plunger core may be forced to move toward the middle portion of the solenoid every time when the solenoid is energized. The spring member is provided for recovering or moving the plunger core away from the middle portion of the solenoid after every striking or hammering operation, for allowing the solenoid to actuate or move the plunger core next time.
However, the striking or hammering forces of the plunger core is small or less, such that the plunger core has to be forced or actuated many times, in order to conduct the striking or hammering operation many times.
In order to improve the small striking or hammering problems, another typical electric percussion tool has been developed to provide a ram propelled device to produce high impact forces against the work pieces. U.S. Pat. No. 3,811,313 to Schut discloses one of the typical impact devices. However, a complicated configuration and a number of members or elements are required to be provided to form the electromagnetic high energy pulse coil and the ram propelled device.
U.S. Pat. No. 3,054,464 to Ondeck, and U.S. Pat. No. 5,760,552 to Chen, et al., and U.S. Pat. No. 6,364,193 to Tsai disclose the other typical electric percussion tools, impact beating tools, or the like and comprise a plunger core slidably received in two or more solenoids which may be actuated in series to actuate the plunger core to impact onto the objects.
However, a large space is required to receive the two or more solenoids, such that the volume of the tools may be greatly increased.
U.S. Patent Application No. US2002/0014344A1 to Geiger et al. discloses a further typical electric percussion tool which includes two coils or solenoids having an axis disposed or extended transverse to the oscillation axis of a working tool. Similarly, a complicated configuration and a number of members or elements are required to be provided to form and to arrange the electromagnetic hammer and a yoke thereof.
In all of the typical electric percussion tools, the spring members are all provided for recovering the plunger core only, and may not be used to force the plunger core while conducting the striking or hammering operations.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional methods for driving electric percussion tools.